Hollow Mesoporous Silica Supported Ruthenium Nanoparticles: A Highly Active and Reusable Catalyst for H₂ Generation from the Hydrolysis of NaBH₄

Abstract

Ru nanoparticles supported on hollow mesoporous silica (HMS), which are prepared via in situ wet chemical reduction, have been investigated as the highly efficient heterogeneous catalyst for H 2 generation from the hydrolysis of an alkaline NaBH 4 solution. Many techniques, including X‐ray diffraction (XRD), transmission electron microscope (TEM), and X‐ray photoelectron spectroscopy (XPS), are used to characterize the as‐prepared nanocatalyst (Ru/HMS). Factors, such as Ru loadings in HMS, catalyst concentration, and solution temperature, on catalytic property and reutilization are investigated in this work. A rate of H 2 generation as high as 18.6 L min −1 g −1 (Ru) using 1 wt% NaBH 4 solution containing 3 wt% NaOH and 40 mg of Ru/HMS catalyst can be reached at room temperature. The minimum apparent activation energy ( E a ) of H 2 generation, obtained by fitting the curve of E a values versus catalyst amount, is determined to be 46.7 ± 1 kJ/mol. The residual catalytic activity of the repeated Ru/HMS still remains 47.7% after 15 runs, which perhaps results from the incorporation of the residual by‐product (NaBO 2 ) in the pores of HMS based on the analysis of XPS.